Electric motor assembly



M. ANDxs ELECTRIC MOTOR ASSEMBLY Oct. 29, 1940.

Filed April 30, 1938 2 snags-Shoe'. l

INVENTOR. MATHEW ANDxs A'ITORNEY Oct. 29, 1940. M. ANDls 2,219,552

ELECTRIC MOTOR ASSEMBLY Filed April 30, n1958 2 Sheets-Sheet 2 Fig. 5.

INVENTOR. MATH Ew Amm 5 ATTOINEYS Patented Oct. 29, 1940 UNITED STATES PATENT OFFICE 19 Claims.

My invention relates to improvements inelectric motor assemblies, with particular reference to motors for operating vibrators at high frequency -for hair clipping, shaving clipping and massaging purposes, but also adapted for various other uses.

Objects of my invention are to provide a, compact motor, operable by either direct or alternating current, reversible and operative with equal emciency in either direction, instantly responsive to a starting impulse, and capable of developing vibratory movements of high frequency and maximum power in proportion to the Weight of the motor.

A further object is to provide an improved three-pole motor of greater efliciency for vibrating purposes, and capable of producing sharper strokes of a reciprocated member or lever than any motors heretofore employed for similar pur- 420 poses.

A further object is to provide such a motor with a non-arcing circuit breakenor one in which arcing is reduced to a minimum in proportion to the developed energy.

A further object is to provide an improved assembly of a motor carrying handle or casing, motor, motor starter, circuit breaker, and power transmitting member or lever, whereby increased vibrating efliciency can be attained.

In the drawings:

Figure l is a plan view of my improved motor as it appears when installed in the handle of a hair clipping device, the handle cap being removed to 'expose the motor.

Figure 2 is a sectional view drawn to line 2--2 of Figure 1.

Figure 3 is a sectional view drawn to line 3-3 of Figure 1.

.Figure 4 is a plan view of the motor, with the o top removed and showing its field coil in section.

Figure 5 is a detail showing the starting lever and associated parts in plan, the motor shaft being shown in cross section.

Figure 6 is a detail showing a fragmentary 45 slotted portion of the casing or handle and the exposed operating member of the starter.

Figure 7 is an electrical diagram.

Like parts are identified by the same reference characters throughout the several views.

In the embodiment shown in the drawings, the motor is mounted within a hollow handle I 0, which contains a set of concentric field coils II and I2 (Figure 2), a three-pole armature having its arms I3 provided with arcuate polar faces 55 equi-distant from each other, and a field magnet (Cl. T12- 36) having a central core bar I6 provided with an arcuate polar face or extremity I1 at one end and the other end extended around the field coils in horseshoe form, and provided with polar extremities I8 equi-distant from each other and from the extremity I1 and arcuately faced in a circle concentric to the arcuate polar faces of the armature arms I3.

'I'he armature and the eld magnet are preferably composed of laminated plates. 'I'hose of the field magnet are connected by screws 20 with the bottom portion of the casing I0. The latter is preferably formed of Bakelite or equivalent delectric vmaterial and provided with interior mounting shoulders 22, in which metallic nuts 23 may be embedded, and into which the screws 20 are threaded. The armature shaft 24 is Vertically disposed and mounted in bearing blocks 25 and 26 carried by the Bakelite mounting plates 21. The bearing blocks have pressed fit relationship to the mounting plates 21, whereas the motor shaft 24 has pressed flt relationship to the concentric plates of the armature, whereby the armature and its shaft rotate as a unit. The armature plates are connected with each other by any suitable means to prevent relative rotation. 'I'he bearing blocks are preferably socketed in the armature, whereby to provide elongated bearings without undue vertical extension beyond the mounting plates.

At its upper end the armature shaft 24 is provided with an eccentric 30 which is fixed to the reduced upper end of the armature shaft 24 and rotates between the fork arms 32 of a vibrator lever 33, pivoted at 34 to the forward bolt or screw 2U. In the construction shown, the forked end of the lever 33 vibrates directly underneath the removable handle cap 35.

A downwardly oifset portion is pivoted to the bolt or screw 20, and the power arm of the lever is additionally offset in a downward direction and extended through an opening 36 in the front end of the handle to a vibratory member 31.

In the structure illustrated, the vibratory member 31 may be assumed to be the cutter bar of a hair clipper operating within a cylindrical bore formed in a suitable shear bar. The shear bar may also be of ordinary construction. A compression spring 38 is coiled about the portion of the lever 33 which extends through the opening 3B, and the short arm of the lever is loosely socketed in the cutter bar. The spring holds the cutter bar in pressure contact with the working portions of the shear bar.

A circuit breaker arm 40 is mounted upon a fai yso

resilient support or spring M, having an angleshaped extremity or bracket B2 secured to the Bakelite mounting plate 21 by screws 53. The supporting spring 4I and the circuit breaker arm di! are preferably formed integrally with the bracket 42, and the portion referred to as the arm @D may be stiffened by bending the upper margin of the plate 4i forwardly, as shown in Figure 2, for reenforcing purposes. The free extremity of the arm in is provided with a contact button 55 adapted for registry with a xed contact d@ connected with a supporting bracket 31.

The periodicity of the spring il allows the arm di! to vibrate in correspondence to the speed of the motor.

The motor shaft 24 is triangular in form be-A tween the bearing block 25 and the eccentric 3i). The arm B has a Bakelite wear plate 58 which bears upon the triangularor cam-shaped portion of the shaft, whereby, when the shaft rotates, the arm 40 will be swung to the circuit breaking or Figure 1 position three times during each shaft revolution. A v

For starting the motor I provide the lower end of the motor shaft 24 with a pinion 50, loosely received in an oval=-shaped slot i, formed in Aan enlarged central portion 52 of a starting lever 53. This starting lever has one end loosely pivoted to` a stud 54 which projects upwardlyfrom the bottom wall of the handle or. casing. The lever has a slot 55 to receive the stud .54, and it also has a hook-shaped extremity 55 which engages a flat spring 51, the ends of which are anchored in the Bakelite shoulders of said handle wall.

The operating end of the lever has a knurled finger or thumb piece 60 which is exposed through an arcuate slot 6i, (Figure 6), in the bottom wall of the handle. This end portion of the lever carries one or more rack teeth d3 which project into the oval slot 5i in position for engagement with the teeth of the pinion 5d when the lever is swung in either direction.l If the points of one or both of the rack teeth d3 clash with the point or points of the pinion teeth in a manner which would lock, against further swinging movement, a lever having a iixed pivot, the slot 55 allows the lever to yield axially until its teeth are permitted to slide over the points of the pinion teeth into mesh between them and the succeeding pinion teeth. As soon as the points of the lever teeth have cleared the engaged pin-l ion teeth, the spring 51 retracts the lever to its normal position, thereby bringing its teeth .fully into mesh between the pinion teeth. While this action of the spring 51 might be referred to as a so-called snap action, a snap action is not essential inasmuch as the lever teeth swing in an arc which carries them between unengaged teeth and the succeeding teeth under any normal condition of operation. However, the springtends to hold the lever in its normal position, as shown in Figure 5, and to prevent an abnormal or unnecessary shifting of the lever axially when the teeth clash.

The length of the handle slot 6I is such that the lever teeth 63 will be carried into and out of mesh with the pinion teeth in a single traverse of the lever in either direction, and the-spring 51 tends to hold the lever at the extremity of its stroke in either direction, thus allowing the pinion to rotate freely withthe motor'shaft. With the construction illustrated, I have found that a single throw of the lever in either directlon will almost invariably start the motor, re-

amarte gardless of whether the current is an alternating current or a direct current.

Referring to the electrical diagram shown in .Figure 7, it will be observed that a circuit is escuit breaker xed contact d8, the circuit lareaker/ arm im, 'lead 'i3 and condenser to the inner held coil it, and thence by lead i5 back to the terminal plug i5.

The terminal plugs, condenser, amature, field magnet, and the forward end of the vibrator lever 33 are all axially aligned within the handle, thereby providing a compact motor assembly of small cross section, and 'of such lineal extension that all working parts except the starting lever may be exposed by remo'val of the cap 35. Also, the use of the screws to connect the working, parts with the bottom wall of the handle casing, makes it possible to have the screw heads allexposed when the handle cap is removed, whereby the motor and associated parts may be readily detached from the bottom portion of the casing by merely removing the connecting screws.

It will be observed that. the motor above described has north-south eld poles, i. e., the pole His of one polarity, whereas the poles I8 are of opposite polarity. There are two flux paths, and their lines of force are concentrated in the central pole of the horseshoe. It has been found that such a motor will start more quickly, attain high speed more speedily, -and will operate with greater power than the motors of similar size heretofore designed to be housed in the handle of a hair clipper or other vibrator.

The arcuate polar extremities of the field poles occupy approximately 135 degrees in the circle of revolution.V The arcuate faces of the neld poles are of substantially the same length or aro, and area, as the corresponding faces of the armature arms.

The position of the armature pola; in relation to the eld poles at the instant the shaft cam opens or closes the breaker points depends on the ,direction of armature rotation. In Figure 4, if the rotation is clockwisa'the circuit clos at the instant the armature poles pas out of regisin'y with their respective eld poles.

It will be noted that the starting lever-53 has its teeth 53 located inthe central portion of the oval opening or slot 5i, the two teeth being substantially at opposite sides of the longitudinal center line of the lever. The arcuate-slot 5i is of suincient length to allow these teeth to not only engage the teeth of the pinion 50, but the stroke of the lever will be of sunicient length to allowthe teeth 63 to move beyond the pinion, whereby when the lever completests stroke in either direction the teeth 63 are wholly out of engagement with the pinion and the lever is held in ,either of its extreme positions by the spring 51,

the tension of which is sumcient to prevent the lever from accidentally shifting. Due to the structure of the motor, with its north-south held poles and its self tuning intel'llllli'fel' spring, a single quick stroke of the starting lever is sui'- cientto start the motor in either direction. 'Ihis is true regardless of whether the current is a direct current or alternating.

By employing wholly or partially ded non-,magnetizable nuts and bearing blocks 23, and 26, the durability of the assembly is not affected by the use of relatively soft Vdielectric material ior the casing and laminated material of high magnetic permeability for the armature.

I claim:

1. A vibrator comprising the combination with a hollow handle, a field magnet mounted therein with a magnetic core piece extending longitudinally of the handle and provided at one end with a polar extremity, the other end of said core piece being extended in horseshoe form beyond said extremity and provided with inturned polar extremities equi-distant from each other and the first mentioned polar extremity, a three pole armature having arms for simultaneous registry with the three polar extremities, and an interlrupter operatively connected with the armature.

2. A vibrator comprising the combination with a hollow handle, a field magnet mounted therein with a magnetic core piece extending longitudinally of the handle and provided at one end with a polar extremity, the other end of said core piece being extended in horseshoe form beyond said extremity and provided with inturned polar extremities equi-distant from each other and the first mentioned polar extremity, a three pole armature havingarms for simultaneous registry with the three polar extremities, an interrupter operatively connected with the armature, and provided with a circuit closing spring having a periodicity proportionate to the normal speed of the armature.

3. A vibrator comprising the combination with a hollow support for a vibratory member, a three pole armature mounted in the support with its poles equi-distant from each other, a field magnet having three symmetrically arranged poles ln a circle concentric with the armature poles and correspondingly spaced, two of said poles being of opposite polarity from the third, an armature shaft provided with an eccentric, and a vibratory arm operatively connected to be actuated by said eccentric.

4. A vibrator comprising the combination with a hollow support for a vibratory member, a three pole armature mounted in the support with its poles equi-distant from each other, a eld magnet having three symmetrically arranged poles in a circle concentric with the armature poles and correspondingly spaced, two of said poles being of opposite polarity from the third, an armature shaft provided with an eccentric, a vibratory arm operatively connected to be actuated by said eccentric, a vibratory member adapted to open and close the circuit of the field magnet, and means for actuating said member in one direction as the armature poles move out of registry with the field poles.

5. A motor having a three pole armature, and a eld frame having three pole pieces symmetrically arranged with reference to the armature and provided with an energizing winding on one of them.

6. In an electric motor, a three pole field frame of horseshoe type having a short central frame member of opposite polarity to the other two, and with equi-distant pole pieces symmetrically arranged in a circle within which an armature may be mounted.

7. In an electric motor, the combination of a three pole field frame of horseshoe type having a short central pole piece of opposite polarity to the other two, and a three-armed laminated armature with which the field poles are concentric.

8. In a reversible electric motor, the combination of a laminated three-armed armature, a

field frame having pole pieces concentric to the poles o1' the armature, an energizing winding on one of the eld poles, and a vibratory member adapted to make and break the circuit in timed relationship to the movement of armature arms across the field pole faces.

9. In a mechanism of the described class, a three pole field frame having a short armed pole piece centrally disposed between the arms of the other two, and a three polearmature with which the field poles are symmetrically arranged, said short armed pole piece having an energizing winding establishing plural magnetic circuits with lines of force concentrated in the short central pole piece.

l0. In a mechanism of the described class, a three pole field frame having a short armed pole piece centrally disposed between the arms of the other two, and a three pole armature with which the eld poles are symmetrically arranged, said short armed pole piece having an energizing winding establishing plural magnetic circuits with lines of force concentrated in the short central pole piece, said energizing winding comprising concentric coils wound in the same direction.

11. In a mechanism of the described class, the combination of a hollow support for a vibratory member, a vibratory member mounted at one end of the support, a reversible motor having a three pole armature mounted for rotation in the plane of member vibration, said motor having a shaft extending transversely of the longitudinal axis of the support, a starting pinion mounted on one end of the motor shaft, a lever pivoted to the hollow support and adapted for rack tooth en gagement with the pinion intermediately of the ends of its stroke, said lever and pinion being located within the support, and provided with an exposed lever operating member.

12. In a mechanism of the described class, the combination with a hollow handle, of a reversible motor mounted in the handle with its armature shaft transverse to the handle axis, an eccentric mounted on one end of the shaft, a vibrator lever operatively connected with the eccentric, a starting pinion mounted upon the other end of the shaft, a lever loosely pivoted within the support and adapted for rack tooth engagement with said pinion during an intermediate portion of lever movement in either direction, and means for allowing the lever to yield longitudinally while its teeth are moving into engagement with the pinion teeth, said lever having an operating piece exposed through a slot in the handle of sufcient length to allow the lever to carry its teeth into and out of engagement with the pinion during a single stroke of the lever in either direction.

13. In a mechanism of the described class, the combination with a hollow handle, of a reversible motor mounted in the handle with its armature shaft transverse to the handle axis, an eccentric mounted on one end of the shaft, a vibrator lever operatively connected with the eccentric, a starting pinion mounted upon the other end of the shaft, a lever loosely pivoted within the support and adapted for rack tooth engagement with said pinion during an intermediate portion of lever movement in either direction, and means for allowing the lever to yield longitudinally while its teeth are moving into engagement with the pinion teeth, said lever having an operating piece exposed through a slot in the handle of sufllcient length to allow the lever to carry its teeth into and out of engagement with the pinion during a single stroke of the lever in either direc- 'having two held poles of one polarity and one eld pole of opposite polarity.

i4. In a mechanism of the described class, the combination with a hollow handle, of a reversible motor mounted in the handle with its armature shaft transverse to the handle axis, an eccentric mounted on one end of the shaft, a vibrator lever operatively connected with the eccentric, a starting pinion mounted upon the other end of the shaft, a lever loosely pivoted within the support and adapted for rack tooth engagement with said pinion during an intermediate portion oi lever movement in either direction, means for allowing the lever to yield longitudinally while its teeth are moving into engagement with the pinion teeth, said lever having an operating piece exposed through a slot in thezhandle of suflicient length to allow fthe lever to carry its teeth into and out of engagement with the pinion during a single stroke of the lever in either direction, said motor having a three pole armature, having two'eld poles of one polarity and one field pole of opposite polarity, and a switch for opening and closing the motor circuit timed for operation 'as the armature poles pass out of registry with rthe eld poles. 1 f

15. In a mechanism of the described class, a motor having a three pole armature, concentric eld poles, two of which are of one polarity and one of which is of an opposite polarity, a switch controlling an energizing circuit ofthe field poles and timed for operation while the armature poles are moving out of registry with the eld poles,

lsaid armature having its shaft provided with cam faces for operating fthe switch, and the switchl being provided with a non-ferrous wear plate bearing upon said cam faces, said switch being supported ,by a spring having vibrating.

first mentioned pole face, and fromv each other,

ment of the switch into and out of circuit closing position.

17. An electric motor for a vibrator mechanism, including a three-pole unwound armature mounted for rotation in a circular magnetic field defined by three equi-distant pole pieces arcuately faced in said circle, one of saidv pole pieces having a core provided with plural uni-directional windings, and arms extending around said windings to the other pole pieces, whereby to type, having a short central frame member of opposite polarity to fthe other two.

18. In an electric motor for vibrators and the like, an unwound three-pole armature mounted for rotation within a circle defined by three equidistant arcuately faced eld pole pieces supported by a field .frame of a generally horseshoetype, including a short arm provided with an energizing winding and carrying one of the pole pieces at one end, and a pair/of arms at the other end extending in opposite directions around the winding and carrying the other rtwo pole pieces, whereby the pole piece on the short arm will be of opposite polarity to that of the other two.

19. The combination of a hollow handle having a removable cap and containingterminal plugs,

condenser, motor and vibrator lever, distributed axially within the handle in positions to be exposed by removal of the cap and having detachable, connections with the handle exposed for yrelease when the cap is removed', said motor including a three-pole unwound armature operatively connected with the vibrator lever, and a eld frame of a generally horseshoe type having three equi-distant pole pieces in a circle concentric with rthat of armature rotation, one of the pole pieces being mounted upon the core provided with the winding and the other two being supported from the outer end of the core by side arms extending around the winding substantially as described.

MATHEW ANDIS.

provide a field frame of a generally horseshoe 

